U.S. EPA Renews Approval for Bt Corn

By Cat Lazaroff

WASHINGTON, DC, October 18, 2001 (ENS) - The U.S. Environmental Protection Agency has extended approval for genetically modified Bt corn for an additional seven years, the agency said Tuesday. The decision was applauded by the biotechnology industry, but roundly criticized by environmental and consumer groups.

Bt corn

An ear of Bt corn (Two photos courtesy Agricultural Research Services)
After what the Environmental Protection Agency (EPA) characterized as a comprehensive scientific review, the agency renewed its approval for corn genetically modified with genes from Bacillus thuringiensis (Bt). Bacillus thuringiensis is a naturally occurring soil bacterium that produces a protein toxic to certain insects.

The toxin in its natural form has been used for many years to control insect pests, particularly on organic farms where other, manmade pesticides are banned.

Incorporating the genetic material from Bt into corn plants enables the plants to produce the same toxin and defend against several pest species. The EPA says that scientific studies and a history of successful use have demonstrated that Bt is not toxic to humans or other animals.

"Bt corn has been evaluated thoroughly by EPA, and we are confident that it does not pose risks to human health or to the environment. Consumers should be assured that these corn varieties show no signs of any adverse effects to human health," said Stephen Johnson, assistant administrator of EPA's Office of Prevention, Pesticides and Toxic Substances.

"The safeguards incorporated into these registrations will ensure that farmers can continue to use an effective, low risk pest control alternative, which helps to protect the environment by reducing the amount of conventional pesticides used," added Johnson.


Bt corn reduces the impact of European corn borers on corn crops
The biotechnology industry said the EPA's decision confirms what the industry has maintained all along - that crops engineered to carry the Bt toxin are safe and effective.

"Bt corn is an important tool for food producers that can increase crop yields and protect the environment by reducing the use of conventional pesticides," said Dr. Val Giddings, vice president for food and agriculture at the Biotechnology Industry Organization. "The EPA's approval of continued use for these products sends a strong signal to the rest of the world that these products are safe and offer significant benefits for growers, consumers and the environment."

After a nearly two year long review process, the EPA says it has determined that Bt corn will not pose unreasonable risks to human health or to the environment. Of particular concern during this process were the potential risks to monarch butterflies, which several studies have shown to be vulnerable to the Bt toxin in their larval, or caterpillar, stage.

The EPA requested extensive data from the scientific community in order to better evaluate the risks to monarchs and other harmless insects.

"The scientific evidence demonstrates that Bt corn does not impact monarch butterfly populations," the EPA said.


Monarch caterpillars on a milkweed leaf dusted with pollen. (Photo by Photo by Kent Loeffler courtesy Cornell)
The agency says it has also determined that there will be no effects to endangered species from the use of the currently registered Bt corn products.

Several environmental and consumer groups criticized the EPA's decision to renew the registrations, saying the agency failed to rule out potential impacts on human health from the engineered crops. The coalition announced earlier this month that it is implementing a new allergy testing program for individuals who have suffered unexplained allergic reactions that could be related to genetically engineered corn.

The groups say the program is an attempt to fill the void created by a lack of government testing. On August 24, the coalition met with EPA Administrator Christie Whitman to voice their concerns, and were told by EPA officials that no testing for human allergies to the Bt proteins had been done since it was last recommended by EPA scientific advisors in July.

In the August meeting, coalition members were also told that there were no plans to do any such testing before reregistering Bt corn.

"The agency should gather the evidence needed to assure consumers that Bt corn is safe to eat before it approves the corn for planting," said Larry Bohlen, director of Health and Environment Programs for Friends of the Earth, a coalition member.

The EPA's science advisors recently reviewed two studies on Bt crops that suggest that all Bt crops may cause allergies in susceptible people. The advisors stated in a report to the EPA, "These two studies suggest that Bt proteins could act as antigenic and allergenic sources."

When the agency was questioned at a public hearing at a later date, the agency said they had not conducted any test or studies to evaluate if there was potential allergenicity with these crops.

"The agency has had the ability for several years to design and conduct allergy testing, yet they have refused. They have turned a blind eye on this issue," said Rand.

The Genetically Engineered Food Alert coalition has arranged for lab certified samples of varieties of genetically engineered corn in question to be made available to allergists nationwide. The samples will allow the allergists to perform skin prick allergy tests in their offices for their patients who have suffered unexplained allergic reactions.


The EPA will require Bt corn growers to take steps to protect the environment, such as planting buffers of conventional corn around their fields of genetically engineered corn (Photo courtesy U.S. Department of Agriculture)
The EPA's renewed registrations of the five Bt corn products now on the market include specific requirements for companies to routinely monitor and collect data to ensure that the products' continued use does not lead to insect resistance or unexpected human health or environmental effects. The companies holding registrations for Bt corn are Monsanto, Syngenta, Pioneer/DuPont and Mycogen/Dow.

To ensure that Bt corn continues to be a safe and effective tool for farmers, EPA has also mandated several provisions to help prevent insects from developing resistance to Bt, including requiring buffer areas around fields planted with Bt corn. The agency will also collect increased research data on potential environmental effects from the crops, and improve grower education and stewardship.

The EPA has increased environmental and compliance monitoring requirements, requesting additional data on the persistence of the active Bt protein in soil, field studies on non-target insects, studies examining long term effects on monarch butterfly populations, an additional feeding study for bird species, and monitoring of the behavior of particular pest populations and their movement through the country.

Companies marketing Bt corn seed will be required to monitor for the development of insect resistance, provide annual reports on the effectiveness of resistance management plans, and implement response plans if resistance is detected among pest populations. The companies must also educate growers about the best methods of planting Bt corn to minimize any potential development of insect resistance.

More information on the EPA's decision is available at: http://www.epa.gov/pesticides/biopesticides